Silk corset body nearly done, but too small

I tried on the Silk Corset the other day, and it's really a tight fit. I was going for the 40.2" finished bust size, so I don't know what happened -- maybe my gauge tightened up after I did the swatch.

I don't feel like frogging it, so my sis may be getting a sweater for Christmas. IF blocking doesn't remedy the problem, that is...